I recently purchased a 2007 Yukon XL Denali with 9500 km on it. It has a bit of a rattle in the driver's door, but otherwise it's been fine in the couple of thousand kms I've driven so far--I'm really enjoying it.

2005 Silverado Ext cab w/4.8, purchased in July. Had to reprogram HVAC module to get rid of annoying popping from dual zone system, driver side mirror glass shakes at highway speed. No other problems, I traded a 2007 Honda Element for this truck and i absolutely love it, i wouldn't have anything else.